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Post by kcbernard2000 on Aug 7, 2021 21:09:00 GMT
Hello all, first I think this site is great and I am excited to be here! I am currently rewiring my monitor top from the great posts that I’ve seen here.
Unfortunately, when I got this monitor top the relay wiring was undone, so I’m not sure where it needs to go. I have looked at the shop manual relay wiring, but I’m still unsure. When I plug the unit in, I don’t see the relay armature move, but the unit does hum.
I’d like to post photos, I don’t see an option to do that. Any assistance would be gratefully appreciated!
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Post by cablehack on Aug 8, 2021 2:26:32 GMT
This might help for the relay wiring www.flickr.com/photos/13469158@N05/7672875200/in/album-72157633054818403/The fact that it hums without the relay armature moving suggests the compressor may have been wired so it's bypassing the relay coil. One way this could happen is if the compressor motor has been connected to the heater terminals. This is also an ideal time to check the oil heater is OK (it should measure about 1000 ohms).
Unfortunately there is limited file space here, so most users post any large images or files on hosting sites like google drive or flickr. If you do want to post photos here, it's recommended to reduce the file size (I use the online site picresize.com). To post photos, click on "Reply" on the top right corner, not "Quick Reply" at the bottom. Then you'll see an "Add Attachment" option in the top right. |
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Post by kcbernard2000 on Aug 9, 2021 20:37:55 GMT
Thanks for your reply cablehack...your diagram was just what I needed! What I have done so far... - Rewired from compressor (3wires) to relay
- Set correct relay wiring per your diagram
- Bypassed thermostat for testing purposes
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Post by turbokinetic on Aug 9, 2021 21:43:31 GMT
Thanks for your reply cablehack...your diagram was just what I needed! What I have done so far... - Rewired from compressor (3wires) to relay
- Set correct relay wiring per your diagram
- Bypassed thermostat for testing purposes
Unfortunately, the coil is completely burned out on your relay. This is an extremely bad sign because the same current which flowed through the coil and burned it out; also flowed through the compressor motor winding. The chances are very high that your compressor is also severely burned out. This happens when the compressor gets stuck and for whatever reason the overload fails to trip. To make a test, you can use a plastic object (such as a ballpoint pen) to manually push the relay armature in while the compressor is powered on. This will complete the start circuit. See if this gets it going. EDIT: Sorry I didn't see any details of the control. Do you have the original GE control for this unit? I ask because it contained the overload breaker. If someone installed the wrong control it can cause a burnout of the relay and possibly compressor. If the compressor survived, the relay can be rewound easily. Also, if the control is not original an aftermarket overload device can be added to the circuit to provide the necessary safety function. Sincerely, David |
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Post by cablehack on Aug 9, 2021 23:59:35 GMT
That relay is a worry. For the coil to droop like that, and the overheated winding, it's been passing too much current for too long. A stalled machine that someone bypassed the overload on perhaps?
I would assume that since the motor hums that its run winding hasn't actually overheated to the point of going open circuit, but my concern would be shorted turns from burned insulation. Also, assuming the relay was doing its job, the other question is how long has the start winding been powered up continuously?
Hopefully the compressor comes to life when you try manually starting it, but of course being a CA it might be full of non-condensible gases, so one has to determine whether its a damaged motor or NCG's, if it doesn't start.
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Post by kcbernard2000 on Aug 10, 2021 1:00:16 GMT
Thanks for your reply cablehack...your diagram was just what I needed! What I have done so far... - Rewired from compressor (3wires) to relay
- Set correct relay wiring per your diagram
- Bypassed thermostat for testing purposes
Unfortunately, the coil is completely burned out on your relay. This is an extremely bad sign because the same current which flowed through the coil and burned it out; also flowed through the compressor motor winding. The chances are very high that your compressor is also severely burned out. This happens when the compressor gets stuck and for whatever reason the overload fails to trip. To make a test, you can use a plastic object (such as a ballpoint pen) to manually push the relay armature in while the compressor is powered on. This will complete the start circuit. See if this gets it going. EDIT: Sorry I didn't see any details of the control. Do you have the original GE control for this unit? I ask because it contained the overload breaker. If someone installed the wrong control it can cause a burnout of the relay and possibly compressor. If the compressor survived, the relay can be rewound easily. Also, if the control is not original an aftermarket overload device can be added to the circuit to provide the necessary safety function. Sincerely, David turbokinetic, Yes, The original control is still present, I just took it off and bypassed it for testing purposes. I tried manually moving the relay with power applied and nothing happened, still hums but it did trip a breaker at my house. |
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Post by kcbernard2000 on Aug 10, 2021 1:01:32 GMT
That relay is a worry. For the coil to droop like that, and the overheated winding, it's been passing too much current for too long. A stalled machine that someone bypassed the overload on perhaps? I would assume that since the motor hums that its run winding hasn't actually overheated to the point of going open circuit, but my concern would be shorted turns from burned insulation. Also, assuming the relay was doing its job, the other question is how long has the start winding been powered up continuously? Hopefully the compressor comes to life when you try manually starting it, but of course being a CA it might be full of non-condensible gases, so one has to determine whether its a damaged motor or NCG's, if it doesn't start. It’s not looking good so far, I tried to manually move the relay with power applied and still no dice. I did do a manual purge and it was blowing out gas for a while. |
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Post by cablehack on Aug 10, 2021 2:01:11 GMT
The next thing is to measure what the motor winding resistances are. I don't have the actual resistance values to hand, but roughly expect around 5 ohms for the run winding (black and red) and around 25 ohms for the start winding (black and white). If you've still got access to the motor terminals, it's best to take the measurements there (in case of a wiring fault), but otherwise at the relay will do (provided of course the thermostat is switched on).
If things are looking ok with the winding resistance, it's possible to feed 120V directly into the start winding (white wire) to see if it starts then. If you're lucky and it does start this way, disconnect the start winding as soon as it does so. While doing any tests with the motor powered up like this, keep the tests very short; if it doesn't start in less than about 3 seconds, power down and let it cool for a short time before repeating.
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Post by kcbernard2000 on Aug 10, 2021 2:55:54 GMT
The next thing is to measure what the motor winding resistances are. I don't have the actual resistance values to hand, but roughly expect around 5 ohms for the run winding (black and red) and around 25 ohms for the start winding (black and white). If you've still got access to the motor terminals, it's best to take the measurements there (in case of a wiring fault), but otherwise at the relay will do (provided of course the thermostat is switched on). If things are looking ok with the winding resistance, it's possible to feed 120V directly into the start winding (white wire) to see if it starts then. If you're lucky and it does start this way, disconnect the start winding as soon as it does so. While doing any tests with the motor powered up like this, keep the tests very short; if it doesn't start in less than about 3 seconds, power down and let it cool for a short time before repeating. Thanks, I will try this and report back! |
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